More than 200,000 people registered for tickets to the Live Earth concert at Wembley Stadium, organisers have said.
Blunt is one of 17 acts so far confirmed
Interested fans had 72 hours from Friday to Monday to register before a ballot to distribute the £55 tickets.
Madonna, James Blunt and the Red Hot Chili Peppers are among the 17 acts confirmed for the concert, which aims to raise awareness of climate change.
Those who have secured one of the July show's 60,000 tickets will be informed by text message on Wednesday.
The Wembley show is one of seven planned to take place in major cities around the world over a single 24-hour period.
"Live Earth is featuring the world's biggest artists across all seven continents to unite an enormous global audience to take action against global warming," Live Earth founder and executive producer Kevin Wall said.
"We're not only putting together the world's biggest live shows, we've developed an unprecedented broadcast architecture to reach a truly global audience."
Under pressure from the government and organisers, online auction site eBay banned the sale of Live 8 tickets, which were won through a text contest in 2005.
Live 8 organiser Bob Geldof had branded the attempted sale of the free tickets as "sick profiteering".
This time eBay says that people in the UK who want to sell their £55 Live Earth tickets would be required to donate at least 20% of the final sale price to charity.
A spokesman said that sellers would be strongly encouraged to donate the money to Stop Climate Chaos, the official organisation supporting the Live Earth concert in the UK, or to another charity supporting the climate change agenda.
He added: "Although the charity will have benefited from the original sale of the ticket, we think it makes sense to use our charity fundraising programme to ensure that good causes benefit from the resale of any spare tickets on the site.
"As a result, users who decide to resell their tickets will be required to donate at least 20% of their final value fee to good causes through our charity fundraising platform."
The London show will be broadcast live on BBC television and radio and shown in 120 countries.